Conventionally, a crosslinked polyvinyl chloride resin wire and a crosslinked polyolefin wire are used as electric wires for use in a high-temperature location such as wiring harnesses for automobile. These crosslinked wires are generally electron irradiation crosslinked, or crosslinked under water vapor atmosphere while using a silane functional group in a coating material.
For example, PTL 1 discloses, as a composition for a wire coating member, a resin composition for use by mixing with silane-crosslinkable polyolefin, the resin composition containing 100 parts by mass of polymer that is selected from a group consisting of a thermoplastic resin, rubber and a thermoplastic elastomer, 0.01 to 0.6 parts by mass of organic peroxide, 0.05 to 0.5 parts by mass of silanol condensation catalyst, and 100 to 300 parts by mass of magnesium hydroxide.